Visual counting has attracted significant attention from many research communities due to its broad real-world applicability and its inherently interdisciplinary topic. A notable example in which it is involved is represented by crowd counting, where the goal is to estimate the number of people present at an event [1]}, [2]}. The exponential growth in the world population and urbanization have led to increased sporting events, political rallies, or public demonstrations, resulting in more frequent crowd gatherings in recent years. Therefore, it is essential to analyze crowd behavior in such scenarios; thus, it is not surprising that crowd analysis is a research topic addressed by researchers from different communities (such as sociology [3]}, [4]}, psychology [5]}, physics [6]}, biology [7]}, [8]}, and public safety) since it is of paramount importance for a variety of critical standpoints and a multitude of perspectives, like the social, political or security-related ones. For example, according to their political positions, it is common for different sides (i.e., the organizers and the opposite parts) to claim different numbers for crowd gatherings. But apart from this, many scenarios involving crowd gatherings such as concerts and sports events address the risk of disasters related to the excessive number of present people. In such cases, the number of people can be exploited as an effective trigger for early overcrowding detection and an appropriate future strategy for managing the crowd [9]}, [10]}. Another prominent example of a real-world counting application is evaluating the number of vehicles in urban scenarios, like highways or parking areas [11]}, [12]}. Building automated counting solutions to deal with this problem would allow the development of systems that precisely monitor the evolution of traffic jams. This information would be invaluable for the public authorities in charge of maintaining and planning road infrastructures. Other fields of applications comprise biology, where, for example, counting bacterial cells from microscopic images may be an indicator of the presence of some diseases [13]}, [14]}, [15]}. Also, in the agriculture/farming field, the counting task can help monitor the livestock, estimate the number of fruits on the trees [16]}, or count plants to assess the seedling emergence rate [17]}, [18]}, [19]}. More, counting objects is also important in more wild contexts, like counting animals in ecological surveys to monitor the population of a specific area [20]} or counting the number of trees in an aerial image of a forest. Counting flowers for estimating the start and duration of flowering is instead relevant for demarcating plant growth stages [21]}, [22]}. In contrast, counting leaves and tillers is a trait pertinent to assessing plant health [23]}, [24]}. We show some examples of real-world counting applications in visualcountingapplications.
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